The invention relates to a method for activating a function of a vehicle, which is associated with a key which wirelessly interchanges data with the vehicle.
The function is intended to be able to be activated with the method, in particular from a distance which is too large for interchanging data with the key. It is appropriate here to use a (particularly portable) telecommunications device, for example a mobile radio telephone, which is different from the key in order to pass a command for activating the function to the vehicle via a telecommunications link (via mobile radio).
For example, it is conceivable for the function to be activated to concern the auxiliary heating of the vehicle. The user of the vehicle has parked the latter at an airport, has flown to a different location and is just about to board the aircraft back to the vehicle. The user wants the vehicle to be preheated when he arrives there again. However, in order to operate the auxiliary heating, it must be ensured that the vehicle is on particular terrain where there is no danger of fire. The situation in which another user, for example the user's wife, has moved the vehicle away and the vehicle is then on different terrain than the user thinks should be avoided.
If the desire is therefore to activate a function of a vehicle with the aid of a telecommunications device, rather than with the vehicle key, a sufficient level of safety must be ensured.
DE 10 2009 035 654 A1 discloses the practice of mechanically coupling a vehicle key to a radio module. In this case, provision may also be made for there to be a communication link between the vehicle key and the radio module. However, in DE 10 2009 035 654 A1, all commands are passed to the vehicle solely by the vehicle key. Therefore, it is not possible to activate functions of a vehicle from a distance which is too large for interchanging data with the key.
EP 1 216 900 A1 describes a remote communication system for a motor vehicle, a first communication unit being arranged in the vehicle and a portable second communication unit, for example a key, being wirelessly and communicatively connected to a telecommunications unit, for example a mobile telephone, which can be used to transmit data in a bidirectional manner between the portable communication unit and the first communication unit in the vehicle over long distances, in particular for the purpose of activating a function of the vehicle. In addition, the second communication unit may comprise a biometric sensor in order to identify a user and to prevent unauthorized remote operation of the motor vehicle. Furthermore, the two communication units may comprise an identification unit. In this case, an identification code may be transmitted, for example, from the second communication unit to the first communication unit. If the identification code is accepted by the first communication unit, a communicative link may be established. If a plurality of portable second communication units are associated with the vehicle, each portable communication unit is assigned a rank, with the result that, in the event of contradictory commands from two or more portable communication units, priority is given to that command from the portable communication unit with the higher rank.
US 2006/294429 A1 describes a method for deleting a local operation which was previously carried out, in particular activation of a function of a vehicle. In this case, when a function of a vehicle is activated by a key, data relating to this function, the key ID and the activation time and date are first of all stored in a memory element connected to the key and in a further memory element in the vehicle. If the activated function is intended to be deactivated by a key from a great distance, the information stored in the key is compared with the information stored in the vehicle and the activated function is deactivated only if the items of information correspond. In this case, an item of comparative information is not obtained for the purpose of activating a function.
EP 2 264 980 A1 describes a communication system having a telematic unit fixed to the vehicle and a communication device which is communicatively connected to the telematic unit. In this case, a plurality of communication paths are available, by which the communication device can communicate with the telematic unit and which have a different range. In this case, a suitable communication path can be selected on the basis of the distance between the communication device and the telematic unit. Furthermore, the communication device may also comprise security data for authorizing communication between the communication device and the telematic unit.